---
tag: 017BPGVEE8
kind: concept
name: Principal branch
aliases: [principal-value]
msc: [30A99]
sources:
  - url: https://en.wikipedia.org/wiki/Principal_value
    locator: lead section
same_as:
  wikidata: Q6126499
  wikipedia: Principal value
---

## Summary

The principal branch of a multivalued function is one branch of it that a standard convention chooses, see the [[definition|0YKY4M3KRQ]].
Its values are the principal values. An example is $\operatorname{Log} z = \ln |z| + i \operatorname{Arg} z$ with $\operatorname{Arg} z \in (-\pi, \pi]$.